dried mortar on stone

Weedwacker

What is the best home solution to get dried mortar off of stone ?

tony.g

The usual way to remove OPC mortar staining is a dilute solution of hydrochloric acid This is available as a proprietory solution at builder's merchants or DIY outlets. It is simply brushed on with a scrubbing brush, and then washed off with water.
Some stones and bricks can be discoloured by the process and it is best to try it on an inconspicuous part first.